NS: Common Mars rock can preserve microfossils

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bystander
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NS: Common Mars rock can preserve microfossils

Post by bystander » Thu Apr 29, 2010 3:03 pm

Common Mars rock can preserve microfossils after all
New Scientist Space - 29 April 2010
Life on Mars, if it ever existed, may be easier to find than previously thought. New research on terrestrial rocks suggests that a type of rock common on Mars can preserve fossilised microbial life, rather than erasing evidence of it as previously thought.

Minerals called sulphates, which form in the presence of liquid water, have been found in great abundance on Mars, including at the landing site of NASA's Opportunity rover, Meridiani Planum.

But it has been unclear whether sulphates could preserve evidence of ancient microbial life. The rocks form when sediment compacts and crystallises, a process that – in other sedimentary rocks such as limestone – can crush the edges of microscopic fossils, destroying evidence of their existence.
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Sulphate minerals like those found in Mars' Gale Crater (pictured) could
preserve evidence of past life (NASA/JPL/Arizona State University)


Earth Fossil Find May Lead to Martian Discoveries
Discovery Space News - 29 April 2010
The discovery of fossils in gypsum on Earth may help scientists zero in on fossils containing past life on Mars.

A common mineral widely believed to be a poor vessel for fossils actually contains a treasure trove of ancient life, a discovery that may lead scientists searching for life on Mars to the planet's sweet spot.

Both Earth and Mars have the mineral gypsum, though it hasn't been of much interest to scientists studying ancient life forms because no one believed tiny fossils could last in the soft, water-soluble mineral, also known as calcium sulfate.

But scientists at an astrobiology conference in Houston will report today that microscopic remnants of a diverse collection of algae and phytoplanktons have been found in samples of gypsum that formed six million years ago when the Mediterranean Sea went dry.
Image
Hebes Chasma, located in the Grand Canyon of Mars, is one area where the mineral gypsum has been
found. New studies on Earth show gypsum can preserve fossils. (ESA/DLR/FU Berlin (G. Neukum))

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neufer
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Re: NS: Common Mars rock can preserve microfossils

Post by neufer » Thu Apr 29, 2010 3:53 pm

http://en.wikipedia.org/wiki/White_Sands_National_Monument wrote:
<<Gypsum is rarely found in the form of sand because it is water-soluble. Normally, rain would dissolve the gypsum and carry it to the sea. Since the Tularosa Basin has no outlet to the sea, rain that dissolves gypsum from the surrounding San Andres and Sacramento Mountains is trapped within the basin, and the rain either sinks into the ground or forms shallow pools which subsequently dry out and leave gypsum in a crystalline form, called SELENITE, on the surface. During the last ice age, a lake known as Lake Otero covered much of the basin. When it dried out, it left a large flat area of SELENITE crystals which is now the Alkali Flat.
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White Sands Gypsum plant stands
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The ground in the Alkali Flat and along Lake Lucero's shore is covered with SELENITE crystals which reach lengths of up to one meter. Weathering and erosion eventually breaks the crystals into sand-size grains that are carried away by the prevailing winds from the southwest, forming white dunes. The dunes constantly change shape and slowly move downwind, covering the plants in their path. Some species of plants, however, can grow rapidly enough to avoid being buried by the dunes. Unlike dunes made of quartz-based sand crystals, the gypsum does not readily convert the sun's energy into heat and thus can be walked upon safely with bare feet, even in the hottest summer months. Because the park lies completely within the White Sands Missile Range, both the park and U.S. Route 70 between Las Cruces, New Mexico and Alamogordo are subject to closure for safety reasons when tests are conducted on the missile range.>>
http://en.wikipedia.org/wiki/The_First_Men_in_the_Moon wrote:
<<H. G. Wells's _The First Men in the Moon_ (1901) tells the story of a journey to the moon undertaken by the two protagonists, the impoverished businessman Mr Bedford and the brilliant but eccentric scientist Dr. Cavor. On arrival, Bedford and Cavor find the moon inhabited by an extraterrestrial civilization the two refer to as "SELENITES". The novel can be read as a critique of prevailing political opinions of the period, particularly of imperialism. The theme of a clash between civilizations is reminiscent of Wells's earlier and more famous work, The War of the Worlds. As in The War of the Worlds, it is hinted that the non-human civilization presented might reflect the way human society would develop in the far future.

At the Moon, the two men at first discover a desolate landscape, but as the sun rises, the thick atmosphere of the Moon, frozen out overnight, begins to melt and vaporize. Soon strange fast-growing plants start to grow in the landscape, producing a very thorny vegetation called "bayonet scrub". Bedford and Cavor leave the capsule, but they get lost in the rapidly growing jungle, where strange creatures can be seen. Growing hungry, the pair sample native flora, described as fungus. Soon after ingestion a hazy euphoric state overtakes them, and they wander drunkenly, speaking gibberish.

They are captured by the insect-like Moon men (referred to as "SELENITES", after Selene, the moon goddess), who have formed a relatively advanced society underground. After some time in captivity, Bedford and Cavor manage to flee. They are able to kill several of their captors and numerous other SELENITES due to their superior strength that results partly because of previously having lived in the Earth's stronger gravity. When Bedford and Cavor reach the surface, they devise a plan to locate their spaceship, which involves them separating. Bedford finds his way back to the spaceship and returns to Earth while Cavor becomes injured and is unable to escape recapture by the SELENITES.
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Back in Britain, Bedford undertakes to publish the details of the story, including some additional material from Cavor received through one-way radio transmission from the Moon. Apparently, Cavor had enjoyed a period of relative freedom in the Lunar society, during which a few of their number learned English. He also managed to build or access a radio transmitter, which he uses to tell the story of his time inside the Moon using Morse code. Cavor recounts near everything that happened to him after being re-captured, but some pieces of his story are not received due to curious "interference" with the radio signal. Through these messages, Bedford learns of Cavor's meeting with the "Grand Lunar", who is the ultimate ruler of the SELENITES and the Moon. At this meeting, Cavor inadvertently portrays humanity as predatory, delighting in war, and with little redeeming value. In response, the Grand Lunar decides to cut off all contact with the Earth. Cavor's transmissions end in mid-sentence as he is trying to say how to make cavorite, and his fate is never revealed.>>
Art Neuendorffer

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